This invention relates generally to the field of medical devices and more particularly to a wireless data gathering and transmission system to be used with patients receiving treatment in a hospital.
In a typical patient monitoring environment several electrodes or sensors are attached to a patient and then connected through wires to a Patient Monitor Processor as depicted in FIG. 1. In an operating room, for example, wires from five, six or ten electrocardiogram (EKG) electrodes, an SpO2 sensor, a CO2 sensor, one, two or four pressure transducers, a pressure cuff, one or more temperature transducers and EEG electrodes may have to be connected between the patient and the Patient Monitoring Processor. This presents a particularly complex cable management problem for the attending physician or nurse. Considerable time can be consumed in disentangling the patient when they must be disconnected or transferred to another area of the hospital. Ideally, a reduction or elimination of all of the cable connections between the patient and the Patient Monitor Processor could be achieved. This could be effectively accomplished by the use of two way wireless transmission and reception between one or more Patient Connected Devices and the Patient Monitor Processor while using the same underlying wireless technology.
Wireless data acquisition systems are well known in the biomedical area. For example, U.S. Pat. No. 5,704,351 issued to Mortara discloses a multiple channel biomedical digital telemetry transmitter. Mortara teaches an eight channel biomedical transmitter specifically directed to an electrocardiogram (EKG) signal transmission in the 902 to 928 MHz band. The Mortara device includes input circuitry and an analog to digital converter which receives the input signal from an EKG electrode and converts it to a digital signal which is inputted to a microprocessor. The microprocessor then converts the digital signal to a serial digital output signal which is used to frequency modulate the radio frequency carrier signal for telemetry transmission. The carrier frequency is adjustable within the 902 to 928 MHz band by two manual frequency setting switches. The use of these manual switches is the only adjustment available on the Mortara device and is capable only of manually setting the specific frequency within the 902 to 928 MHz band. The input circuitry and analog to digital converter are not adjustable or adaptable to accept different input signal characteristics. Further, the Mortara device cannot be adjusted by programming or otherwise to operate in any other frequency band. Finally, the Mortara device is only a transmitter and is unable to receive RF or other signals to control its operation.
Similarly, U.S. Pat. No. 5,755,230, issued to Schmidt et al. discloses a device for monitoring a physiological signal, in particular an EEG, and transmitting the signal by RF to a receiver. Like Mortara, the Schmidt et al. device cannot be modified or adjusted to receive inputs from different physiological sensors.
U.S. Pat. No. 5,579,775, entitled DYNAMIC CONTROL OF A PATIENT MONITORING SYSTEM, issued to Dempsey discloses a patient monitoring system with a telemetry subsystem which monitors and transmits an RF signal representing the signals it receives from one or more physiological monitoring instruments. Unlike Mortara and Schmidt et al., Dempsey teaches a receiving subsystem which can receive RF signals in a backchannel arrangement in order to control the operation of the system. However, Dempsey does not include the capability to adjust or modify the input by programming or otherwise in response to different physiological signals. The device relies on separate monitoring sections in order to accommodate different physiological signals such as EEG, EKG and SpO2.
U.S. Pat. No. 5,417,222, also issued to Dempsey, discloses a portable processor which may be interconnected to a telemetry monitor at the I/O port. The Dempsey ""222 device includes a telemetry monitor comprising a physiological monitor which receives selected physiological signals indicating a specific physiological condition of the patient. The physiological monitor is a specific type of monitor that reads signals of a specific physiological function such as EKG, for example. In the event that a different physiological function is to be monitored such as EEG a different physiological monitor must be employed. In particular, Dempsey ""222 discloses the interface of a programmable processor (the Hewlett Packard 100LX palmtop processor) with a physiological monitor. The device is not able to adapt or change the physiological monitor, by software or otherwise, to accept different physiological signals.
The Fluke corporation manufactures a wireless data acquisition system under the trade name of xe2x80x9cWireless Loggerxe2x80x9d. The xe2x80x9cWireless Loggerxe2x80x9d is an integration of Fluke""s Hydra Data Logger, a portable instrument monitor/analyzer, which accepts wired external inputs, with an RF modem. The Hydra Data Logger includes a universal input module which accepts and conditions external inputs. The resulting signals are transmitted by the modem to another modem interconnected to a personal computer. The separate modem and universal input module are relatively large and consume up to ten watts of power. The operation of the system is not software programmable. RF Neulink markets a similar system utilizing the VHF (136-280 MHz) and UHF (403-512 MHz) bands.
U.S. Pat. No. 6,167,258, entitled PROGRAMMABLE WIRELESS DATA ACQUISITION SYSTEM, issued to Schmidt et al, discloses the use of a signal processing module which is capable of accepting multiple external inputs having different characteristics and ranges. The ""258 Schmidt et al. device, through programming, converts and conditions the external inputs, generates an RF signal encoded with data corresponding to the external inputs and transmits the signal to a base station.
U.S. Pat. No. 6,230,049, entitled INTEGRATED SYSTEM FOR EEG MONITORING AND ELECTRICAL STIMULATION WITH A MULTIPLICITY OF ELECTRODES, issued to Fischell et al., discloses an integrated EEG monitoring and electrical stimulation system that has a wireless link between a patient electronics module and an EEG analysis workstation.
In general, the prior art attempts at monitoring and transferring patient data are illustrated in FIGS. 1 and 3. In none of these cases is the same patient connected device used to transfer data to either a patient monitor processor or a central station with the same underlying wireless technology. Accordingly, a need remains for a system based on the same underlying technology that allows patient monitoring data collected by multiple monitors connected to a patient to be wirelessly transferred to another device such as a Patient Monitoring Processor for the purpose of displaying, synchronizing and processing the data.
The present invention is a system that allows patient monitoring data collected by one or more sensors or devices connected to a patient to be wirelessly transferred to another device, such as a patient monitoring processor. The transferred data may be displayed, synchronized and otherwise processed. The patient monitoring processor may be located in close proximity to the patient or at some distance depending on the mode of operation of the patient monitoring system. The wireless data transfer operates in both directions, that is, data can also be transferred from the patient monitor processor to the patient connected devices. The same patient connected device is used to transfer and receive data to or from either a patient monitor processor, a central station or both depending on the state of the patient without any alteration of the patient connected device hardware.